In modern aircraft having integrated cockpits, discrete navigation and autopilot systems operate separately, but work together. One major concern with navigation and autopilot systems is pilot mode awareness. Excessive intricacies and mode proliferation in modern aircraft navigation and autopilot systems make it difficult for pilots to understand system operation in each of multiple different operational modes. Annunciation of the different operational modes is provided to help the pilot to understand. Mode annunciation is integrated for the separate navigation and autopilot systems, with operational mode annunciation being provided by a single annunciation. Presently, operational mode annunciation is accomplished using only alphanumeric text which is presented on one of the cockpit displays. For example, the characters “VS” are presented on a cockpit display such as a primary flight display (PFD) to indicate current operation in the vertical speed mode, the characters “IAS” are presented to indicate operation in the indicated air speed mode, and the characters “FPA” are presented to indicate operation in the flight path angle mode.
Other modes include vertical navigation (VNAV) mode whereby the aircraft flies according to a stored set of vertical waypoints that are preprogrammed in a flight management computer system (FMCS), altitude hold (ALT) mode for maintaining current altitude, flight level change (FLCH) mode for changing flight level, and other flight modes. There can be in excess of 20 different alphanumeric mode enunciators, which are a combination of numerous control parameters involving different aircraft attitude, speed, and thrust settings. While these and other alphanumeric mode enunciators are helpful, they require the pilot to expend resources interpreting their significance before the information can be used.